1. Department of Geosciences Colorado State University Fort Collins Colorado 80523‐1482 USA
2. Department of Zoology and Physiology University of Wyoming Laramie Wyoming 82071 USA
3. Earth and Environmental Sciences Division Los Alamos National Laboratory Los Alamos New Mexico 87545 USA
4. Fort Collins Science Center U.S. Geological Survey (USGS) Fort Collins Colorado 80526 USA